Is it difficult to charge 2 batteries in your car while driving. I have a 'Deep Cycle Marine' battery that I like to keep charged between fishing trips
2007-09-26 13:04:19 · 5 answers · asked by Ferret 5 in Cars & Transportation ➔ Maintenance & Repairs
If you have room for a battery mount, go for it. You have to install an isolator, such as used in motorhomes, that keep the batteries separate. One will be used for starting and running the car, and the isolator, allows both to charge, without overcharging either one, or drawing more charge current than is safe. Isolators are available for different alternator sizes, typically 70, 90, 120, and 165 amp, your car probably has a 70 amp so there is no problem. If you don't have room for a secure bracket for the second battery, keep it plugged in at home with a small trickle charger.
By the way, do not hook up two batteries in parallel, always use an isolator. The reason is simple. If one battery is low, and the two are hooked in parallel, it will drain the other to the same level, and they will then both be low. It is called a parasitic drain. The only time you hook batteries up in parallel is to jumpstart a car with a low or dead battery, and you disconnect the 2nd battery right after starting the car.
2007-09-26 13:14:57 · answer #1 · answered by Fred C 7 · 0⤊ 0⤋
Two automotive batteries being charged together must be connected in parallel, that's negative to negative and positive to positive, and the resulting voltage will be 12 volts.
If the same two batteries were to be connected in series, that's positive to negative , and positive to negative, the result would be 24 volts. (do not do this!)
I would not recommend doing that. If you charge the battery at home, it should hold the charge for at least a couple of days. I know whenever I buy a new battery that has been in storage a long time, it still has enough charge to crank my vehicle.
Another thing to keep in mind is that normally, when two or more batteries are connected, they should be of the same capacity,ie, cranking amps, etc.
One other thing you can do, is buy a duplicate battery and connect them in parallel. That will double the amps output.
So, the consensus is that it is not recommended that you do as you asked.
2007-09-26 13:32:34 · answer #2 · answered by billy brite 6 · 0⤊ 0⤋
That kinda depends on how big the alternator is and what accessories you are running while you are trying to charge the 2nd battery. If you're driving with the headlights on and the A/C blowing full blast and a mega-boom amp, chances are there's not a lot left over for charging the second battery.
If you keep those off, then yeah, theoretically it can be done. Whether it's a good idea is another story. Remember, a battery charger is a whole lot less expensive than a new alternator. They were never designed to put out full power for extended periods of time.
Rick
I'm a retired ASE Master/L-1 Technician. I still keep current with the latest automotive technology. Visit my blog for cool articles and TSB's: http://free-auto-repair-advice.blogspot.com
2007-09-26 13:10:21 · answer #3 · answered by Anonymous · 0⤊ 1⤋
This would then be 24 volts if charged together. Is your system 24 volts?
I'd charge one in a home charger or change batteries over after a couple of hours etc.
2007-09-26 13:11:05 · answer #4 · answered by Anonymous · 0⤊ 2⤋
You should not continually charge a deep cycle, it will shorten it's life considerable. They should be discharged and then recharged. They are not meant for starting use as they have no cca to spesk of.
2007-09-26 13:45:17 · answer #5 · answered by tronary 7 · 0⤊ 0⤋